President Corazon Aquino shows none of her past leniency toward the Philippine insurgency in allowing the arrest and prosecution of a communist leader. In fact, Mrs. Aquino congratulated the military for capturing Rodolfo Salas, alleged commander in chief of the communist New People's Army, on the streets of Manila Monday night. Also captured were his wife and a driver.

``This is a commendable accomplishment on the part of our law-enforcement agencies,'' she said in a statement yesterday. ``I shall expect these responsible government agencies to continue providing for public safety and security and enforcing the law.''

Her decision to retain Mr. Salas, despite having released communist leaders last March after she took power from Ferdinand Marcos, has jeopardized cease-fire talks with the rebels, whose negotiators demand Salas's release.

Just two days before Salas's arrest, the communist negotiators had given in to Aquino's demand for a 30-day cease-fire. Increasingly, she has been threatening to expand the military's anti-insurgency activities.

But Aquino and her top aides contend that the capture has no connection with the talks. The government's chief negotiator, Agriculture Minister Ramon Mitra, said: ``We never complained that while we were talking they were ambushing some of our people in the provinces.''

Aquino aides also say the communists must agree soon to a truce. ``The government keeps the door open for a cease-fire,'' the President said.

Slowly, Aquino appears to be losing patience with the communists, whom she offered amnesty if they gave up their weapons. In April, she criticized the rebels for not joining her in ``the task of national recovery,'' while praising the military for doing so. Speaking at Harvard University last month, she cited ``a terrible strain'' on the military, which at her request has suspended much -- but not all -- of its anti-insurgency activities. This has allowed rebels to continue attacks against soldiers and public figures.

The bloodless capture of Salas, however, is in line with her stated goal to use nonviolent tactics.

``Only nonviolence . . . cuts through to its objective with the precision of a surgical knife. . . ,'' she said recently. In the past, she noted that under the Marcos regime Filipinos gave the military no intelligence about the rebels' movements, indicating that the people would now do so.

Aquino has also outlined a ``radical change in military strategy, away from the reckless expenditure of force to a more discriminating and effective application of it. . . .''

Ironically, Salas's capture brings Aquino one step closer to her original demand for peace talks, which she made last April. ``Negotiations will be with the top leadership of the Communist Party or there will be none,'' she said.

But the talks began in August with no public assurance that the communist negotiators were top-level Communist Party leaders. Rather, Antonio Zumel, Satur Ocampo, and his wife, Carolina Malay Ocampo, said they were just representatives of the National Democratic Front, a leftist coalition alleged only to be dominated by the Communist Party.

The rebels have been temporarily set back by the capture of their leader, but will regain their ability to wage an insurgency, according to the armed forces chief of staff, Gen. Fidel Ramos.

General Ramos said Salas had committed ``many crimes,'' mainly through his organization of so-called ``sparrow units'' (communist assassination squads). Salas is also alleged to be responsible for a 1974 killing of five American Navy officers. The Justice Ministry is now preparing charges against him.